1. Field of the Invention
The present invention generally relates to an image processing apparatus, an image processing method and a navigation apparatus, which can obtain a distance to a road edge and a road width on the basis of an image signal from an image taking device (e.g., a motion picture camera) in a vehicle, which is presently traveling. The present invention also relates to a program storage device for storing a program and a computer data signal embodied in a carrier wave, which enable a computer to function as such an image processing apparatus.
2. Description of the Related Art
There is a navigation apparatus, which detects a present position of a vehicle as a movable body, and displays the detected present position together with a road map around it, to thereby conduct a route guidance. In this type of the navigation apparatus, a large storage capacity record medium (e.g., a CD-ROM, a DVD-ROM or the like), on which map data are recorded, is equipped, and is used to generate the display data displayed on a display picture plane. The map data on the record medium include data related to the shape of the road and various data for display as well as road width information accompanying those. Therefore, it is possible to read out the road width information corresponding to the road on which the vehicle is presently traveling, and the road width of this road can be grasped.
However, according to the above mentioned navigation apparatus, the road width information included in the map data does not indicate an accurate road width, but indicates an inaccurate and rough road width of the road, such as 5.5 m to 8 m for example. Thus, it is not possible to obtain an accurate road width information finely corresponding to each point of the road.
Further, it is also desired not only to merely recognize the road width of the road but also to obtain the distance to the road edge in a real time manner so as to make the best use of it for a safe driving operation of the vehicle. On the other hand, if the principle of the tigonometrical survey is adapted by setting a plurality of cameras, the distance can be measured in a stereoscopic manner, although it is possible to obtain the distance to the road edge, the structure of the apparatus becomes complicated and the cost thereof is certainly increased.
It is therefore an object of the present invention to provide an image processing apparatus and an image processing method, which can obtain a distance to the road edge such as a wall surface etc., or a road width by means of a relatively simple configuration on the basis of an image taken from a presently traveling vehicle, and also a navigation apparatus, which can perform a warning or a guidance so as to secure a safe driving operation for a driver, in correspondence with a result of the image processing of the image processing apparatus, as well as a program storage device for storing a program and a computer data signal embodied in a carrier wave which enable a computer to function as such an image processing apparatus.
The above object of the present invention can be achieved by an image processing apparatus provided with: an image taking device for taking an image in a forward direction of a movable body and outputting an image signal corresponding to the taken image; a movement vector detecting device for detecting a movement vector for each area of the image taken by the image taking device, on the basis of the image signal while the movable body is moving; and a distance calculating device for setting a standard line at a predetermined image position crossing a road edge with respect to the image taken by the image taking device, and calculating the distance to the road edge on the basis of a distribution of the movement vector on the standard line.
According to the image processing apparatus of the present invention, the image taking operation in the forward direction of the movable body such as a vehicle is performed and the image signal is outputted by the image taking device while the movable body is presently moving. The image signal at one time point and the image signal at another time point are compared with each other, so that the movement vector for each area is detected. The characteristic of the movement vector on the standard line set in the image at one pixel portion corresponding to a road surface and that corresponding to a construction on the road edge are different from each other. Thus, it is possible to judge the road edge and calculate the distance to the road edge by obtaining the inflection point of the movement vector. Therefore, the calculated distance can be utilized for securing a safety in driving, aiding the navigation operation and the like, so as to improve the safety and the convenience of the movable body by means of a rather simple configuration.
In one aspect of the image processing apparatus of the present invention, the image processing apparatus is further provided with a road width calculating device for calculating a road width of the road, on which the movable body is moving, on the basis of the distance to the road edge calculated by the distance calculating device.
According to this aspect, the road width of the road on which the movable body is presently moving can be calculated on the basis of the distance to the road edge calculated in correspondence with the forward image of the movable body. For example, the road width can be obtained by adding the left and right distances. Therefore, it is possible to secure the safety in driving by using this road width, and store the road width data in correlation with map data, so that the function and safety of the navigation for the movable body can be improved.
In another aspect of the image processing apparatus of the present invention, the image processing apparatus is further provided with a margin degree judging device for judging a degree of margin with respect to the road edge of the road, on which the movable body is moving, on the basis of the distance to the road edge calculated by the distance calculating device.
According to this aspect, on the basis of the distance to the road edge calculated in correspondence with the forward image of the movable body, the margin degree with respect to the road edge of the movable body is judged. Therefore, it is possible to recognize such a condition that the movable body is too close to the road edge and have no margin or clearance, to thereby improve the safety of the movable body.
In another aspect of the image processing apparatus of the present invention, the image processing apparatus is further provided with a calibration device for calibrating an image taking direction of the image taking device on the basis of the detected movement vector.
According to this aspect, upon the operation of the image processing apparatus, the image taking direction of the image taking device is calibrated by detecting the movement vector and then determining a disappearance point for example. Therefore, the image process can be performed in consideration with the scattering of the condition of fixing the image taking device, and a rather simple calibration can be performed since the movement vector is utilized.
In another aspect of the image processing apparatus of the present invention, the image signal comprises frame image data, which has a predetermined frame cycle, as a unit, and the movement vector detecting device detects the movement vector on the basis of two consecutive frame image data.
According to this aspect, the object of the image process is the frame image data outputted for each frame cycle, and the above described image process is performed by using the two consecutive frame image data. Therefore, the image process is performed always in a real time manner while the movable body is moving, so that the image processing apparatus dealing with the actual condition of the movable body speedily can be realized.
The above object of the present invention can be also achieved by an image processing method of performing an image process on the basis of an image signal, which is outputted from an image taking device for taking an image in a forward direction of a movable body and outputting the image signal corresponding to the taken image. The image processing method is provided with: a movement vector detecting process of detecting a movement vector for each area of the image taken by the image taking device, on the basis of the image signal while the movable body is moving; and a distance calculating process of setting a standard line at a predetermined image position crossing a road edge with respect to the image taken by the image taking device, and calculating the distance to the road edge on the basis of a distribution of the movement vector on the standard line.
According to the image processing method of the present invention, the image taking operation in the forward direction of the movable body such as a vehicle is performed and the image signal is outputted by the image taking device while the movable body is presently moving. Thus, it is possible to judge the road edge and calculate the distance to the road edge by obtaining the inflection point of the movement vector. Therefore, the calculated distance can be utilized for securing a safety in driving, aiding the navigation operation and the like, so as to improve the safety and the convenience of the movable body by means of a rather simple configuration.
In one aspect of the image processing method of the present invention, the image processing method is further provided with a road width calculating process of calculating a road width of the road, on which the movable body is moving, on the basis of the distance to the road edge calculated by the distance calculating process.
According to this aspect, the road width of the road on which the movable body is presently moving can be calculated on the basis of the distance to the road edge calculated in correspondence with the forward image of the movable body. Therefore, it is possible to secure the safety in driving by using this road width, and store the road width data in correlation with map data, so that the function and safety of the navigation for the movable body can be improved.
In another aspect of the image processing method of the present invention, the image processing method is further provided with a margin degree judging process of judging a degree of margin with respect to the road edge of the road, on which the movable body is moving, on the basis of the distance to the road edge calculated by the distance calculating process.
According to this aspect, on the basis of the distance to the road edge calculated in correspondence with the forward image of the movable body, the margin degree with respect to the road edge of the movable body is judged. Therefore, it is possible to recognize such a condition that the movable body is too close to the road edge and have no margin or clearance, to thereby improve the safety of the movable body.
In another aspect of the image processing method of the present invention, the image processing method is further provided with a calibration process of calibrating an image taking direction of the image taking device on the basis of the detected movement vector.
According to this aspect, the image taking direction of the image taking device is calibrated by detecting the movement vector. Therefore, the image process can be performed in consideration with the scattering of the condition of fixing the image taking device, and a rather simple calibration can be performed since the movement vector is utilized.
In another aspect of the image processing method of the present invention, the image signal comprises frame image data, which has a predetermined frame cycle, as a unit, and the movement vector detecting process detects the movement vector on the basis of two consecutive frame image data.
According to this aspect, the object of the image process is the frame image data outputted for each frame cycle, and the above described image process is performed by using the two consecutive frame image data. Therefore, the image process is performed always in a real time manner while the movable body is moving, so that the image processing method dealing with the actual condition of the movable body speedily can be realized.
The above object of the present invention can be also achieved by a navigation apparatus for performing a route guidance from a present position of a vehicle to a destination on the basis of map data, provided with: a sensor device including a vehicle speed sensor for detecting a moving speed of the vehicle; an image taking device for taking an image in a forward direction of the vehicle and outputting an image signal corresponding to the taken image; a movement vector detecting device for detecting a movement vector for each area of the image taken by the image taking device, on the basis of the image signal while the vehicle is moving; and a distance calculating device for setting a standard line at a predetermined image position crossing a road edge with respect to the image taken by the image taking device, and calculating the distance to the road edge on the basis of the detected moving speed and a distribution of the movement vector on the standard line.
According to the navigation apparatus of the present invention, the vehicle speed is detected by the sensor device, the image taking operation in the forward direction of the vehicle is performed and the image signal is outputted by the image taking device. Then, the movement vector for each area is detected. Thus, it is possible to judge the road edge and calculate the distance to the road edge by obtaining the inflection point of the movement vector. Therefore, the calculated distance can be utilized for securing a safety in driving, aiding the navigation operation and the like, so as to improve the safety and the convenience of the movable body by means of a rather simple configuration.
In one aspect of the navigation apparatus of the present invention, the navigation apparatus is further provided with a warning device for warning that the vehicle is close to the road edge if the calculated distance to the road edge is smaller than a threshold value, which is set in advance.
According to this aspect, on the basis of the distance to the road edge, it is judged that the vehicle is too close to the road edge, and warns it to the driver, so that the safety and the convenience of the vehicle can be further improved.
In another aspect of the navigation apparatus of the present invention, the navigation apparatus is further provided with: a margin degree judging device for judging a degree of margin with respect to the road edge of the road, on which the movable body is moving, on the basis of the distance to the road edge calculated by the distance calculating device; and a warning device for warning that the vehicle is close to the road edge if the judged degree of margin is smaller than a predetermined standard value.
According to this aspect, on the basis of the distance to the road edge calculated in correspondence with the forward image of the movable body, the margin degree with respect to the road edge of the movable body is judged. In accordance with this margin degree, it is warned that the movable body is too close to the road edge, to thereby improve the safety of the movable body.
In another aspect of the navigation apparatus of the present invention, the navigation apparatus is further provided with a road width calculating device for calculating a road width of the road, on which the vehicle is moving, on the basis of the calculated distance to the road edge.
By constituting in this manner, the road width of the road on which the movable body is presently moving can be calculated. For example, the road width can be obtained by adding the distances on the left and right sides. Therefore, it is possible to secure the safety in driving by using this road width, and store the road width data in correlation with the map data, so that the function and safety of the navigation for the vehicle can be improved.
In this aspect having the road width calculating device, the navigation apparatus may be further provided with a road width data memory for storing road width data corresponding to the calculated road width in correlation with the map data such that the road width data can be updated.
By constituting in this manner, the road width data corresponding to the calculated road width is stored into the map data memory such that it can be updated. Therefore, since the road width data of the road on which the vehicle has moved can be held, and can be utilized later on when the vehicle moves on the same road again, it is possible to aid the function of the navigation apparatus.
In this aspect having the road width calculating device, the navigation apparatus is further provided with: a traffic lane judging device for judging a traffic lane, on which the vehicle is presently moving, on the basis of calculation results of the distance calculating device and the road width calculating device; and a warning device for warning an appropriate traffic lane, on which the vehicle is to move, by correlating the judged traffic lane with a route to the destination.
By constituting in this manner, when the vehicle moves on a road having a plurality of traffic lanes, the traffic lane, on which the vehicle is presently moving, is judged by the traffic lane judging device, on the basis of the distance to the road edge and the road width. Then, the judged traffic lane is correlated with the optimum route to the destination, and the warning is given to the driver so as to drive the vehicle on the appropriate traffic lane corresponding to the optimum route. Therefore, it is possible to caution the driver to drive the vehicle on the traffic lane corresponding to the optimum route, so that the comfortable navigation apparatus can be realized.
In this aspect having the traffic lane judging device, the warning device may warn the appropriate traffic lane if the judged traffic lane is not coincident with the appropriate traffic lane.
By constituting in this manner, the judged traffic lane is correlated with the optimum route to the destination, and the appropriate traffic lane is warned to the driver when it is judged that the vehicle is not moving on the appropriate traffic lane. Therefore, while unnecessary warning is avoided when the vehicle is moving on the appropriate lane, the comfortable navigation apparatus can be realized by virtue of minimal warning.
In this aspect having the traffic lane judging device, the warning device may warn that the judged traffic lane is coincident with the appropriate traffic lane if the judged traffic lane is coincident with the appropriate traffic lane.
By constituting in this manner, the judged traffic lane is correlated with the optimum route to the destination, and, if it is judged that the vehicle is moving on the appropriate traffic lane, this fact is warned to the driver. Therefore, by informing the drive that the vehicle is moving on the appropriate traffic lane, the comfortable navigation apparatus giving the safety feeling to the driver can be realized.
A program storage device readable by a computer, tangibly embodying a program of instructions executable by the computer to perform an image process on the basis of an image signal, which is outputted from an image taking device for taking an image in a forward direction of a movable body and outputting the image signal corresponding to the taken image. The image process includes: a movement vector detecting process of detecting a movement vector for each area of the image taken by the image taking device, on the basis of the image signal while the movable body is moving; and a distance calculating process of setting a standard line at a predetermined image position crossing a road edge with respect to the image taken by the image taking device, and calculating the distance to the road edge on the basis of a distribution of the movement vector on the standard line.
According to the program storage device of the present invention, as the computer reads in and executes the program stored therein, it is possible to realize the above described image processing apparatus of the present invention on the computer.
The above object of the present invention can be also achieved by a computer data signal embodied in a carrier wave and representing a series of instructions which cause a computer to perform an image process on the basis of an image signal, which is outputted from an image taking device for taking an image in a forward direction of a movable body and outputting the image signal corresponding to the taken image. The image process includes: a movement vector detecting process of detecting a movement vector for each area of the image taken by the image taking device, on the basis of the image signal while the movable body is moving; and a distance calculating process of setting a standard line at a predetermined image position crossing a road edge with respect to the image taken by the image taking device, and calculating the distance to the road edge on the basis of a distribution of the movement vector on the standard line.
According to the computer data signal embodied in the carrier wave of the present invention, as the computer downloads and executes the program in the computer data signal, it is possible to realize the above described image processing apparatus of the present invention on the computer.